Exertional fat embolism after hip joint replacement: a case report

INTRODUCTION We present the case of a patient with exertional fat embolism on isolated exercise of his right leg two and four months after right total hip joint replacement. His immediate post-operative period had also been complicated by an acute episode of chest pain and hypotension, treated as acute coronary syndrome. To the best of our knowledge, this is the first reported case of exertional fat embolism following orthopedic surgery. CASE PRESENTATION A 71-year-old Caucasian man underwent elective cementless total right hip joint replacement. His acute post-operative period was complicated by an episode of chest pain and hypotension. This was treated as acute coronary syndrome. Two months later, a routine stress echocardiography demonstrated a shower of small, echodense bubbles in his right heart, reproduced on exercise of his right leg but not his left. Computed tomography pulmonary angiography excluded pulmonary thromboemboli. A technetium-99m colloid scan confirmed pulmonary fat emboli. Similar findings occurred again four months after the operation but had resolved at six months. CONCLUSIONS Fat embolism is a well-described phenomenon in the acute setting after long-bone trauma or intramedullary manipulation, and the rare fat embolism syndrome can be fatal. Exertional fat embolism months after joint replacement, however, is an undescribed phenomenon that may have implications in the sub-acute post-operative phase. This may be of particular interest to those involved in orthopedics, cardiology and rehabilitation, but the large volume of patients undergoing joint replacements may broaden the clinical scope of this unusual presentation far beyond these specialties.